In the past, systems have been proposed for introducing addition agents into vessels and/or ladles through the bottom thereof. However, no such systems are known to be in current use. One ancient patent suggests apparatus for introducing a small one shot charge of finely divided material into the bottom of the container of molten metal (See U.S. Pat. No. 165,929). Yet another very old patent suggests extruding metallic sodium or other metals soft enough to be extruded into the bottom of a ladle (See U.S. Pat. No. 1,938,716). A recent patent suggests carrying gas entrained addition agents through the bottom of the vessel (See U.S. Pat. No. 3,980,469). None of the prior art patents provide for the introduction of large quantities of addition agents without the use of an inert gas carrier which may create substantial dust pollution in the vicinity of the vessel as it emerges from the bath.
Filed of even date herewith are two patent applications Application Ser. No. 924,079 entitled "Method of Introducing Addition Agents Into a Vessel of Molten Metal" and Application Ser. No. 924,080 entitled "Method of Introducing Calcium and Calcium Alloys Into Molten Metal." The system and/or the apparatus disclosed herein are particularly suitable for practicing those methods.